<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style type="text/css">
			*{
				/* box-sizing: border-box; */
			}
			#d1{
				width: 100px;
				height: 100px;
				border-width: 10px;
				border-style: solid;
				padding: 50px;
			}
			#d2{
				width: 100px;
				height: 100px;
				border-width: 10px;
				border-style: solid;
				padding-top: 30px;
				text-align: center;
				/* padding-left: 20px; */
				box-sizing: border-box;
			}
		</style>
	</head>
	<body>
		<div id="d1">
			
		</div>
		<div id="d2">
			居中
		</div>
	</body>
</html>
